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class: center, middle

# Proxy

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# Also known as

* Surrogate

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# Intent

* Provide a surrogate or placeholder for another object to control access to it.

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# Applicability

* Protection proxy limits access to the real subject.
* Virtual proxies are used when an object is expensive to instantiate.
* Caching proxies are used to cache expensive calls to the real subject.
* Remote proxies are used in distributed object communication.
* Smart proxies are used to implement reference counting and log calls to the object.

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# Diagram

.center[![Alt text](proxy-concept.png)]

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# Tutorials

* Blog http://java-design-patterns.com/blog/controlling-access-with-proxy-pattern/
* Source code http://java-design-patterns.com/patterns/proxy/

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